The present invention relates to an oil pan for an internal combustion engine, which is mounted on an underside of an engine cylinder block, and more specifically to an oil pan having a baffle plate.
Japanese Patent Application First Publication No. 7-42523 discloses an oil pan for an internal combustion engine, which has a double-walled structure including an inner pan and an outer pan with a very small clearance therebetween. Lubricating oil drained from the engine is introduced to the very small clearance to form a thin oil layer therein. Each of the outer and inner pans includes a deep oil collecting portion and a shallow oil collecting portion which are disposed adjacent to each other in a longitudinal direction of the engine. The shallow oil collecting portion is disposed near an engine rotating part such as a crankshaft. A baffle plate extends over the inner-and outer pans to restrain an oil level of the lubricating oil within the oil pan from swinging during operation of a vehicle. The baffle plate has a plurality of oil guide holes through which the lubricating oil dripped from a part, for instance, a crankshaft journal, near the oil pan is collected at the shallow oil collecting portion.
It will be noted that such a conventional oil pan as the above-described related art is complicated by the double-walled structure and therefore the lubricating oil drained from the engine and the lubricating oil dripped from the adjacent part such as the crankshaft journal are collected at the separate portions, i.e., the clearance between the inner and outer pans and the shallow oil collecting portion of the inner pan. Further, in the conventional oil pan, the baffle plate, except the oil holes thereof, covers the entire shallow oil collecting portion and further no measure is taken for forcing the lubricating oil collected at the shallow oil collecting portion toward the deep oil collecting portion. This will prevent the lubricating oil dripped from the crankshaft journal from being smoothly directed to the deep oil collecting portion via the oil guide holes and the shallow oil collecting portion. In such a case, the lubricating oil within the shallow oil collecting portion tends to be contacted with the crankshaft and stirred thereby. If the lubricating oil is stirred by the contact with the crankshaft, air is undesirably mixed in the lubricating oil. In addition, if the crankshaft is contacted with an oil level of the lubricating oil within the shallow oil collecting portion, friction loss caused by the contact therebetween will be increased.
It is an object of the present invention to provide an oil pan having a simple structure and capable of quickly collecting a lubricating oil at a deep oil collecting portion through a shallow oil collecting portion.
It is a further object of the present invention to provide an oil pan capable of controlling an oil level of the lubricating oil collected at the shallow oil collecting portion so as not to be in contact with an engine rotating part.
According to one aspect of the present invention, there is provided an oil pan for collecting a lubricating oil drained from an internal combustion engine and a lubricating oil dripped from a crankshaft of the engine, said oil pan being disposed near the crankshaft, comprising:
a wall including a first oil collecting portion and a second oil collecting portion that are adapted for collecting the lubricating oils, said first and second oil collecting portions being connected with and adjacent to each other in a longitudinal direction of the engine;
a first baffle plate cooperating with the first oil collecting portion of the wall to define a first oil passage extending along the longitudinal direction of the engine, said first oil passage being disposed downstream of a rotating direction of the crankshaft perpendicular to the longitudinal direction of the engine, said first oil passage having an inlet portion open in a direction opposed to the rotating direction of the crankshaft;
a second baffle plate cooperating with the first oil collecting portion of the wall to define a second oil passage extending along the longitudinal direction of the engine and spaced from the first oil passage in a lateral direction of the engine perpendicular to the longitudinal direction, said oil passage being disposed upstream of the rotating direction of the crankshaft; and
a plurality of oil guides guiding the lubricating oil drained from the engine to the first and second oil passages, said plurality of oil guides being disposed on the first and second baffle plates, respectively;
wherein said first and second oil passages are so arranged as to force the lubricating oil collected at the first oil collecting portion toward the second oil collecting portion.
According to a further aspect of the present invention, there is provided an oil pan for collecting a lubricating oil drained from an internal combustion engine and a lubricating oil dripped from a crankshaft of the engine, said oil pan being disposed near the crankshaft, comprising:
a first oil collecting portion for collecting the lubricating oils;
a second oil collecting portion for collecting the lubricating oils, said second oil collecting portion being adjacent to the first oil collecting portion in a longitudinal direction of the engine and connected therewith;
first wall means for defining the first and second oil collecting portions;
a first oil passage extending along the longitudinal direction of the engine and disposed downstream of a rotating direction of the crankshaft perpendicular to the longitudinal direction of the engine, said first oil passage having an inlet portion open in a direction opposed to the rotating direction of the crankshaft;
a second oil passage extending along the longitudinal direction of the engine and spaced from the first oil passage in a lateral direction of the engine perpendicular to the longitudinal direction, said second oil passage being disposed upstream of the rotating direction of the crankshaft;
second wall means cooperating with the first oil collecting portion of the first wall means to define the first oil passage; and
third wall means cooperating with the first oil collecting portion of the first wall means to define the second oil passage;
wherein said second and third wall means forcibly guide the lubricating oil collected at the first oil collecting portion toward the second oil collecting portion.
According to a still further aspect of the present invention, there is provided an oil pan for collecting a lubrication oil drained from an internal combustion engine and a lubricating oil dripped from a rotating part of the engine, said oil pan being disposed near the rotating part, comprising:
a first oil collecting portion for collecting the lubricating oils;
a second oil collecting portion for collecting the lubricating oils, said second oil collecting portion being adjacent to the first oil collecting portion in a longitudinal direction of the engine and connected therewith;
first means, downstream of a rotating direction of the rotating part, for enabling the lubricating oil collected at the first oil collecting portion to be introduced thereinto by wind force caused upon rotation of the rotating part and be forced toward the second oil collecting portion; and
second means, upstream of the rotating direction of the crankshaft, for preventing the lubricating oil collected at the first oil collecting portion from being influenced by the wind force and for forcing the lubricating oil collected thereat toward the second oil collecting portion;
wherein said first and second means cooperate to facilitate collection of the lubricating oil through the first oil collecting portion and control an oil level of the lubricating oil collected at the first oil collecting portion so as not to be in contact with the rotating part.